JMH: You missed the point. The point is that considering that so many Gedolei Yisroel did — and do — pronounce it as a Choilem, it is clear and obvious that Choilem is a correct Mesorah.
I’m not advocating anyone switch from cholem to choilem. I’m saying that everyone is correct to stick with whatever their custom is. Whether it is cholem or whether it is choilem.